Humidifier



5. C STIMSON Dec. 7, 1937.

HUMIDIFIER glwgcntm:

Filed ,Nov. 13, 1955 Stream/g6.

Patented Dec. 7, 1937 PATEN HUMIDIFIER Samuel Carl Stimson, WinstonSalem, C., ,as-, signorto The Bahnson Company, Winston- Salem, N. 0., acorporation of North Carolina Application November 1 3, 1935, SerialNo'. 49,611

This invention relates to humidifiers of the type including a fan forcreating an air current and a rotating disk for projectingwater'ag'ain'st abutments or teeth,"'t11e water being therebydisintegrated into afine mist which evaporates rapidly in the aircurrent. I

. Humidifiers of-this type have been in use for many years "and," ingeneral, include an electric motorhaving a shaft'which extends beyondopposite sides of the motor casing, the fan and disk being secured tooppositeends of the motor shaft. Typical constructions are shown in thepatents to Fries, 947,300, dated Jan. 25, 1 910, Bahnson, 1,267,166;dated May 21,-1913', and impson, 1,=966;8'72,dated July 173 1934; Theefii'ciency of such devices is not primarily dependent uponthe quantityof water'which can be discharged into the air current, butuponthemaxim-um quantity which can beevaporated without an accompany.ing entrainment i of' unevaporated particles. Such"unevaporatedparticlesmay cause serious damagewhen deposited uponmachinery-or the goods, such as paper, thread or cloth, which areemployed in the manufacturing processes. The effective evaporative"capacity of a" humidifier therefore depends upon th-quantityand velocityof the air in-inotion, andupon the velocity at which thewater isprojected from therotating disk. It is obviousthat such factors asexcessive wear, vibration and noise, and power consumption have placedratherdefinite structural limits upon the speed and diameter of thewater-im pelling disks of the prior devices, and have thus set ratherdefinite limits for the maximum capacitybfthe prior humidifiers. J;Objects of the present invention'are to provide humidifiers of the fanand rotating disk type which are characterized by an increased evapora-'tive efficiency and by quiet operation. An object is to provide ahumidifier including a fan, a water-impelling disk and power mechanismfor rotating the fan at 'one speed and the disk at a much higher speed.More particularly, an object is toprovide a humidifier including a lowspeed motor for directly driving 'a low speed fan, and a step-up drivebetween the motor and disk for driving the latter at high speed. Afurther object is to provide a humidifier of the type state'd, in whichthe high speed disk andlits, associated casing are of less diameter thanthe fan blades, thus facilitating the formation of a small diamet-er airstream into which the water mist is discharged.

These and other objects and advantages of the invention will be apparentfromthe following specification when taken with theaccompanying drawing;in which:

T OFFICE i Fig. 'l is a fragmentary schematic" view or an embodiment ofthe invention which includes sep aratemotorelement'sfor the fan andwaterdisk; Fig. 2 is a side elevation, with'parts in section,

. of a construction in-which the motor drives the water disk throughagear train; and Fig. 3 is a fragmentary front elevation of the gearbox.I i' In Fig. l of the drawing, the reference numeral l identifies thecasing" of'ian induction motor which has a low' speed field 2and'associated armature 3 for rotating the fan F and a high speed field4 and armature 5 for rotating the disk D. The fan and disk are securedto the respective shafts 3', 5' that are in axial alin-ement' andsupported in independent sets of bearings. Power is supplied to themotor from an alternat ing current line L'ffwhich may befthe usualGOcycle system customarily employed for light and power. The low speedsection is connected directly across the line L, and the high speed section of the motor is fed through a frequency mul tiplier 6 and highfrequency lin'eL'. As indicated by the legends; the speed of the fan maybe'1750 R. P. M.;and that of the disk approximately 7000 R. P. Ml in atypical case! The fan speed of 1750 R. PL M. will be recognized as astandard speed for induction motors operating on a 60 cycle power lineand, while'other speeds maybe employed, this speed has been found to bequite satisfactory for quiet operation and high air displacement at lowpower consumption. The higher speed of the water-impelling disk D willbe selected in accordance with other design require; inents toprovidethe mostsatisfactor'yconstruction for the particular conditions whichare to be met. The frequency multiplier may be of the frequency changeror the motor-generator type and may be designed to provide any desiredspeed for the disk D.

As shown in Figs. 2 and 3, the invention may be embodied in a singlemotor construction by mounting one rotating element, such as the fan F,directly upon the shaft 1 of motor M, and driving the other rotatingelement through a changespeed transmission. A bracket 8 supports themotor M, a fan guard 9, and a drain pan IE which is positioned below thedisk D to carry away any water which drains from the casing l l. Thecasing l l and the ring member l2 which supports a row of teeth l3 atthe periphery of the disk D preferably take the form of dished orconcave annular members which may be spun from copper or otherappropriate materials. Water is delivered to the inner face of the disk,adjacent its center, through a pipe I4, and the flow may be controlledby any appropriate mechanism.

As distinguished from prior devices of this general type in which thedisk D is mounted directly upon the shaft 1 of motor M, the disk issecured to a shaft I5 which is supported in roller bearings I6, I! thatare in axial alinement with the outer bearing I8 of the motor shaft I.The gear box or casing I9 has a partition wall in which the bearing I 6is mounted and a main cover plate 20 which carries the bearing IT. Astub shaft 2I is journalled in bearings 22, 23 that are mounted on thegear box I9 and a small cover plate 24, respectively. The gear box ispreferably apertured to receive bolts 25 that engage in the threadedopenings by which the front frame member of the conventional motordesign was secured to the main casing to enclose the shaft bearing I8.The gear train includes a large gear 26 on shaft I and meshing with thesmall gear 21 on the stub shaft, and the large gear 28 on the stub shaftmeshing with a smaller gear 29 on the disk shaft I5. Quiet operation anda balancing of end thrust is obtained by using helical gears of oppositeslope for'the two sections of the gear train. When the bolt holes of thegear box are so located as to match with the threaded bores of the motorcasings of humidifiers of prior design, the gear box, disk and casingsmay be used as a replacement unit to modernize the old style machines.This change involves only the removal of the old large size disk andcasing, and the shortening of the motor shaft to receive gear 26.

In one embodiment of the invention which had a high evaporativeefficiency, the gear train sections each had a, 2 to 1 ratio and thedisk was therefore rotated at four times the speed of the fan.Particular attention is directed to the fact that disk D and easing IIof the Fig. 2 construction are of substantially smaller diameter thanthe fan F. 'Prior attempts to obtain high evaporative capacity had ledto the use of disks of increasing sizes and some commercial designs haveincluded 16 inch disks. Humidifiers constructed in accordance with thisinvention have developed a greater evaporative capacity with 9 inchdisks than can be obtained with the 16 inch disks of the prior designs.The reduction in disk diameter is explained by the much higherperipheral speed obtained when the disk is rotated at a higher speedthan can be employed for the fan.

The smaller diameter of the disk is accompanied by a reduction in thesize of the disk casing II, and this results in further improvement inthe operating characteristics. The air stream created by the fan F isnot greatly diverted or expanded as it passes around the casing of motorM and the small diameter and smoothly curved disk casing II. The aircurrent which passes over the edge of the casing I I is therefore arelativly high velocity stream or hollow column of air which is welladapted to evaporate the mist of water which is created by the disk;Dand teeth I3.

. The invention therefore provides both a more efficient atomization ofthe Water and an air stream of higher velocity and more compact shapefor evaporating the atomized water. Both results are obtained withoutmaterially increasing the power consumption and without increasing thenoise of operation or the wear on the moving parts.

Although it would be possible to secure the disk to the shaft of a highspeed motor, and to use a speed reduction drive to the fan, theillustrated arrangement of a direct fan drive from a low speed motor isto be preferred as it is characterized by minimum noise and wear.

It isto be understood that there is some latitude in the design andconstruction of the mechanism, whether mechanical or. electrical, whichis employed to drive the axially alined fan and disk at differentspeeds. -Various changes which may be made in the several parts andtheir relative arrangement fall within the spirit of my invention as setforth in the following claims.

I claim:

1. A unit adapted to be used with a humidifier of the type including amotor having a casing and a shaft, and a fan and a disk mounted uponopposite ends of said motor shaft; said unit comprising a gear boxadapted to be secured to said motor casing, a shaft in said gear box, adisk mounted on said gear box shaft, a gear adapted to be'secured to theshaft of the motor, a transmission train connecting'said gear and saiddisk shaft for rotating the latter at higher speed than said gear, anatomizer ring at the periphery of said disk, and a casing enclosing saidatomizer ring and disk, said second casing being adapted to be attachedto said motor casing.

2. A unit as claimed in claim 1, wherein said gear is a helical gear andsaid transmission train includes a stub shaft in said gear box, ahelical gear on said stub shaft and meshing with said first gear, and apair of meshing gears on said stub shaft and said disk shaft,respectively, said second pair of gears being helical gears of aninclination opposite to that-0f said first pair of meshing gears.

' SAMUEL CARL STIMSON.

